DIGITAL.CSICThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.https://digital.csic.es2019-05-25T15:01:56Z2019-05-25T15:01:56Z5041Phylogenetic Reassessment of Antarctic Tetillidae (Demospongiae, Tetractinellida) Reveals New Genera and Genetic Similarity among Morphologically Distinct SpeciesCarella, MircoAgell, GemmaCárdenas, PacoUriz, María Jesúshttp://hdl.handle.net/10261/1359692018-07-10T08:52:59Z2016-08-26T12:38:18ZTitle: Phylogenetic Reassessment of Antarctic Tetillidae (Demospongiae, Tetractinellida) Reveals New Genera and Genetic Similarity among Morphologically Distinct Species
Authors: Carella, Mirco; Agell, Gemma; Cárdenas, Paco; Uriz, María Jesús
Abstract: Species of Tetillidae are distributed worldwide. However, some genera are unresolved and
only a few genera and species of this family have been described from the Antarctic. The
incorporation of 25 new COI and 18S sequences of Antarctic Tetillidae to those used
recently for assessing the genera phylogeny, has allowed us to improve the resolution of
some poorly resolved nodes and to confirm the monophyly of previously identified clades.
Classical genera such as Craniella recovered their traditional diagnosis by moving the Antarctic
Tetilla from Craniella, where they were placed in the previous family phylogeny, to
Antarctotetilla gen. nov. The morphological re-examination of specimens used in the previous
phylogeny and their comparison to the type material revealed misidentifications. The
proposed monotypic new genus Levantinella had uncertain phylogenetic relationships
depending on the gene partition used. Two more clades would require the inclusion of additional
species to be formally established as new genera. The parsimony tree based on morphological
characters and the secondary structure of the 18S (V4 region) almost completely
matched the COI M1-M6 and the COI+18S concatenated phylogenies. Morphological
synapomorphies have been identified for the genera proposed. New 15 28S (D3-D5) and
11 COI I3-M11 partitions were exclusively sequenced for the Antarctic species subset.
Remarkably, species within the Antarctic genera Cinachyra (C. barbata and C. antarctica)
and Antarctotetilla (A. leptoderma, A. grandis, and A. sagitta), which are clearly distinguishable
morphologically, were not genetically differentiated with any of the markers assayed.
Thus, as it has been reported for other Antarctic sponges, both the mitochondrial and
nuclear partitions used did not differentiate species that were well characterized morphologically.
Antarctic Tetillidae offers a rare example of genetically cryptic (with the traditional
markers used for sponges), morphologically distinct species.
Description: 32 páginas, 12 figuras, 1 tabla
2016-08-26T12:38:18ZThe dynamics of a Mediterranean coralligenous sponge assemblage at decennial and millennial temporal scalesBertolino, MarcoCosta, GabrieleCarella, MircoCattaneo-Vietti, R.Cerrano, CarloPansini, MaurizioQuarta, GianlucaCalcagnile, LucioBavestrello, G.http://hdl.handle.net/10261/1514002018-07-10T08:53:00Z2017-06-14T06:38:45ZTitle: The dynamics of a Mediterranean coralligenous sponge assemblage at decennial and millennial temporal scales
Authors: Bertolino, Marco; Costa, Gabriele; Carella, Mirco; Cattaneo-Vietti, R.; Cerrano, Carlo; Pansini, Maurizio; Quarta, Gianluca; Calcagnile, Lucio; Bavestrello, G.
Abstract: This paper concerns the changes occurred over both decennial and millennial spans of time
in a sponge assemblage present in coralligenous biogenic build-ups growing at 15 m depth
in the Ligurian Sea (Western Mediterranean). The comparison of the sponge diversity after
a time interval of about 40 years (1973–2014) showed a significant reduction in species richness
(about 45%). This decrease affected mainly the massive/erect sponges, and in particular
the subclass Keratosa, with a species loss of 67%, while the encrusting and cavity
dwelling sponges lost the 36% and 50%, respectively. The boring sponges lost only one
species (25%). This changing pattern suggested that the inner habitat of the bioconstructions
was less affected by the variations of the environmental conditions or by the human
pressures which, on the contrary, strongly affected the species living on the surface of the
biogenic build-ups. Five cores extracted from the bioherms, dating back to 3500 YBP,
allowed to analyse the siliceous spicules remained trapped in them in order to obtain taxonomic
information. Changes at generic level in diversity and abundance were observed at
500/250-years intervals, ranging between 19 and 33 genera. The number of genera showed
a sharp decrease since 3500–3000 to 3000–2500 YBP. After this period, the genera regularly
increased until 1500–1250 YBP, from when they progressively decreased until 1000–
500 YBP. Tentatively, these changes could be related to the different climatic periods that
followed one another in the Mediterranean area within the considered time span. The recent
depletion in sponge richness recorded in the Ligurian coralligenous can be considered relevant.
In fact, the analysis of the spicules indicated that the sponges living in these coralligenous
habitats remained enough stable during 3000 years, but could have lost a significant
part of their biodiversity in the last decades, coinciding with a series of warming episodes.
Description: Este artículo contiene 19 páginas, 10 figuras, 3 tablas.
2017-06-14T06:38:45ZDescription of two new genera (Antarctotetilla, Levantiniella) and a new species of TetillidaeCarella, MircoUriz, María Jesúshttp://hdl.handle.net/10261/1685402018-08-16T11:58:17Z2018-08-10T08:03:34ZTitle: Description of two new genera (Antarctotetilla, Levantiniella) and a new species of Tetillidae
Authors: Carella, Mirco; Uriz, María Jesús
Abstract: Tetillidae is a sponge family distributed all over the world but with some genera apparently endemic from the Antarctic
and Subantarctic (the “Antarctic clade”). Species identification results tricky due to the similarities of their morphological
characters. However, molecular phylogenies have helped to resolve the family taxonomy. The last phylogenetic study on
Tetillidae suggested the creation of two new genera: Levantiniella and Antarctotetilla. Lenvantiniella, from Middle East
Mediterranean Sea, was previously classified within Cinachyrella, from which it differs in the small rounded surface cavities,
distinctive from true porocalices. Antarctotetilla has up to now an Antarctic distribution, and harbors species wrongly
classified within Tethya, Craniella, or Tetilla. The main differences of Antarctotetilla to other Tetillidae genera are the
presence of pores grouped in small areas, and a poorly-defined cortex (pseudocortex). This study aims to re-describe in
detail the species of Tetillidae that belong in the two above mentioned new genera, and to highlight that molecular phylogenies
should be combined with morphological analyses to improve taxonomical decisions. We also describe a new
Tetillidae species with a hair-like hispidation, which we name Antarctotetilla pilosa nov. sp. Furthermore, the types of
Tethya coactifera and T. crassispicula (Lendenfeld, 1907) were reexamined because of some morphological similarities
with Antarctotetilla. The minibarcode sequences (a small COI fragment) placed them within the Antarctic clade harboring
Antarctotetilla and Cinachyra, but did not resolve their genus position. A morphological revision, however, suggests placing
T. coactifera in Antarctotetilla, while T. crassispicula, which owns porocalices and a spicule-reinforced cortex, appeared
to belong in Cinachyra.
Description: Este artículo contiene 27 páginas, 2 tablas, 16 figuras
2018-08-10T08:03:34ZAsexual reproduction and heterozygote selection in an Antarctic demosponge (Stylocordyla chupachus, Suberitida)Carella, MircoAgell, GemmaUriz, María Jesúshttp://hdl.handle.net/10261/1726742018-11-28T11:28:16Z2018-11-26T13:27:48ZTitle: Asexual reproduction and heterozygote selection in an Antarctic demosponge (Stylocordyla chupachus, Suberitida)
Authors: Carella, Mirco; Agell, Gemma; Uriz, María Jesús
Abstract: Antarctic bottoms harbor stable, benthic communities, subjected to low temperatures. Environmental stability may promote
the asexual (clonal) reproduction of sponges to maintain adapted genotypes to those particular conditions. Stylocordyla
chupachups forms patchy populations across the Antarctic continental shelf. Individuals are mostly similar in size without
distinct cohorts, which indicates fast growth of the new recruits. Settlement of incubated (clonal?) functional sponges may
accelerate sponge growth and success at early colonization phases. To analyze the weight of clonal reproduction in the species,
a genetic study was performed on three close populations using eight polymorphic microsatellite loci that were designed
from massive sequencing. The three study populations showed a relatively low genetic diversity and low loci polymorphism
(from 2 to 6 alleles). The estimators of genetic structure, the Analysis of the Molecular Variance (AMOVA), and the presence
of private alleles indicated low but significant structure between the populations. A relatively high rate of asexual reproduction
(ca. 25% of the individuals) was detected. The program MLGsim found five identical multilocus genotypes (MLGs) with
an asexual origin. An excess of heterozygotes (in five out of the eight loci genotyped) was found, which suggests a positive
selection mechanism for heterozygotes. The relatively high rates of asexual reproduction may be the result of adaptation to
the environmental stability, while heterozygote selection would help maintain some genetic diversity in the populations. S.
chupachups has been reported to be one of the first sponge species recolonizing bare areas resulting from iceberg scouring,
which indicates a high species fitness and adaptation to Antarctic bottoms. Two out of the three study populations showed
bottleneck, which may indicate a recent founder effect and supports the pioneer nature of this species.
Description: Este artículo contiene 9 páginas, 2 tablas, 1 figura
2018-11-26T13:27:48Z